Counterbalancing mechanism



Sept. 26, 1933. R. BLOSS r AL 1,928,245

COUNTERBALANCING MECHANI SM Filed Aug. 8, 1930 l N V EN TORS.

Elk/1am? 25/055:

Patented Sept. 26, 1933 UNITED STATES I 1,928,245 I corm'mmssmncme rmcrmmsu Richard R: Bloss m m 0. Hell,

Columbus, Ohio Application August 8, 1930. Serial No. 473,854

4Claims.

Our invention relates to method and apparatus for counterbalancing well umping mechanism. It has to do, particularly, with the provision of a novel form of counterbalance that is designed to 6 be attached to and work in conjunction with a crank of an ordinary well drilling and pumping mechanism, although it is not necessarily limited in use to oil wells. I

Variations in loads in oil well drilling during any complete cycle of operation makes it highly desirable to provide a counterbalancing device to compensate for this variation and, more particularly, to counterbalance the drop of the tools and assist in the elevation thereof. The gradually increasing length of the string of tools makes it desirable to be able to vary the counterbalancing effect of a counterbalancing device with reference to the center line of the crank, so that the counterbalancing effect on the sucker rods can be retarded or advanced with relation to the center line of the crank.

One of the objects of our invention is to provide a simple counterbalancing device which may be readily applicable to a crank of standard form.

Another object of our invention is to provide a crank counterbalance which may be maintained in juxtaposition to the crank and readily moved into cooperative position with relation thereto.

Another object of our invention is to provide a crank counterbalance which is so constructed with relation to the standard form of crank that,

.with a minimum number of parts, it may be maintained rigidly in connection with the crank with complete fre'edomfrom movement relatively thereto. 7

Another object of our invention is to provide a crank counterbalance which may be readily disconnected from the crank and adjusted to such a position that its weight is neither suspended from the crank or crank shaft, although it is in a position fromwhich it may be readily adjusted to the proper position for connection to the crank.

Another object of our invention is to provide a counterbalancing device which is designed to be connected to the crank and which may have its parts adjusted to vary its counterbalancing effect with reference to the center line of the crank without adjusting the device itself with 50 reference to the crank.

Our invention preferably contemplates the provision of a counterbalancing body casting which is designed to be connected to the crank shaft in between the jack post and the crank arm. This body casting may be secured to the crank shaft by means of a split bearing which is preferably provided with bolts of sufllcient length to permit lowering of the body casting ontoa shelf or other supporting means whereby the crank shaft will be relieved of the weight there- .of. Suflicient clearance is provided between the inner face of the crank hub and the outer face of the jack post permit the body casting to slide into or out of interfering relation with the standard crank arm. Our body casting is'preferably of such form that, when moved into interfering relation to the crank, it will partially embrace a portion of this crank with a wedging action. Our body casting is also preferably provided with a plurality of detachable weights arranged in separate groups so that the relative weight of each group may be varied to retard or advance the counterbalancing effect with relation to the center line of the crank.

This application is a continuation in part of our application upon Counterbalancing devices, Serial No. 167,924, filed February 14, 1927.

The preferred embodiment of our invention is shown in the accompanying drawing wherein similar characters of reference designate corresponding parts and wherein:

- Figure 1 is a perspective view of our'counterbalancing device removed from the shaft.

Figure 2 is a section taken on line 2-2 of the counterbalancing device shown in Figure l but illustrating the position of the counterbalancing device when it is connected to the crank arm.

Figure 3 is a side elevation partly in section of a crank shaft and crank arm with our counter- .balancing device shown detached and lowered to its supporting shelf.

Figure 4 is a section taken on line 4-4 of Figure 2. V

In the drawing, our novel apparatus and the apparatus which we preferably useto perform our novel methodis shown in application to a crank shaft 1 having one end thereof mounted in ajack post 2 and having the same end thereof. provided with a crank arm 3 of standard form.

It will be noted that the crank arm has its hub 4 spaced from the jack post 2 a substantial distance.

, Designed to be suspended upon the crank shaft is a counterweight structure comprising a body casting 5 which is preferably-of generally seg- 195 mental form. Its upper-end is provided with a split bearing structure comprising a lower half of a journal formation and a complemental journal cap '7. This split bearing structure is design d. to embrace the shaft 1' in between the jack post 2 and the hub 4 of the crank arm, as shown in Figures 2 and 3. As illustrated by a comparison of these figures, the counterweight structure suspended from the crank shaft 1 is adapted to be adjusted to either one of the positions shown.

The body casting 5 is further provided with a flared socket member 8 disposed vertically in the center of the body casting directly below the split I bearing structure thereof. In the base of this flared socket member and extending entirely through the casting is a series of regularly spaced holes 9. This flared socket member is preferably of a structure to embrace the rib 10 of the usual standard crank or it may be of a structure to embrace any portion of a standard crank which may be. of slightly different form.

The split bearing of the body casting is preferably provided with comparatively long bolts 11 and nuts 12 for securing the cap in proper embracing relation to the crank shaft 1. These bolts are made of greater length than usual so that they may be utilized, when the counterweight is disconnected from the crank arm, for lowering this counterweight into aposition of rest upon a shelf The crank arm is preferably provided with a wrist pin 14 having an elongated shank 16 which is threaded as at 17 for the reception of a nut 18. As shown in Figure 2, this shank 16 of the wrist pin is capable of extending through one of the holes 9 in the body casting and the nut 18 may then be utilized to hold the counterweight firmly connected'to the crank arm with its flared socket embracing it with a wedging action.

- 'It will be noted that our body casting 5 is adapted to be provided with two sets of supplemental weights 19 and 20. One of the features of our method consists in the fact that these weights are so disposed upon the body casting that they may be utilized to retard or advance the counterbalancing effect of the counterweight upon the sucker rods. Therefore, by using more weights in the group 19 than in the group 20, or vice versa, we can alter the center of gravity of the counterweight to retard or advance the counterbalancing eil'ect on the sucker rods.

In operation, the counterweight is rendered operative by moving it in the position shown in Figure 2. In this position, the flared socket member 8 embraces the rib 10 of the crank arm with a wedging action. It is maintained in this position by tightening the nut 18 upon the shank 16 of the wrist pin. When it is desired to move the counterweight away from operative relation to the crank arm, the nut 18 is removed, the nuts 12 upon the bolts ll'loosened-and the counterweight is then moved to the left (considering Figure 2) until the split bearing is in abutting relation to the jack post 2. At this time, the

counterweight is out of interfering relation to the crank arm, assuming that the elongated wrist pin 14 has been removed or. replaced by a wrist pin of normal length. If desired, the nuts 12 may then be adjusted upon the bolts 11 to permit the counterweight to rest upon the shelf 13 and be entirely supported thereby.

It will be seen that we have provided an extremely simple structure wherein the counterweight is readily applicable to a crank of standard form. It will also be understood that independent bolts and nuts may be provided for passing through the holes 9 and through one or more wrist pin holes not in use to secure the counterweight to the crank arm. It will also be understood that, if desired, the crank arm may be provided with perforated ears integrally formed thereon for cooperation with properly provided apertures in the counterweight to secure the crank arm and counterweight together.

It will likewise be seen that we have provided a novel method by which the counterbalancing effect on the sucker rods may be retarded or advanced with relation to the center line of the crank. Furthermore, this may be accomplished effectually with a minimum complication of structure.

Having thus described our invention, what we claim is:

1. A crank counterbalance comprising a body portion constructed for suspension between the jackpost and the crank-arm of a pumping mechanism, said body portion having a wedge-shaped socket upon that face thereof which is opposite to the inner face of the crank-arm.

2. A crank counterbalance comprising a ,body portion constructed for suspension between the jackpost and the crank-arm of a pumping mechanism, said body portion having an elongated wedge-shaped socket on that face thereof which is opposite the inner face of the crank of the mechanism.

- 3. The combination of a crank-arm having a wedge-shaped lug upon its inner surface, and a counterbalance weight having a wedge-shaped socket designed to flt over saidwedge-shaped lug.

4. The combination of a crank-arm having an elongated wedge-shaped lug upon its inner surface, and a counterbalance weight constructed for suspension upon the crank-shaft, said counterbalance weight having an elongated wedgeshaped socket for cooperation with the said lug of said crank-arm, said parts being movable into cooperative relation to adjustment of said counterbalance weight axially of the crank-shaft which carries said crank-arm. 

